Just a guess, but I think this is the relevant part of the error log:
Caused by: org.eclipse.core.internal.dtree.ObjectNotFoundException: Tree element ‘/C%%Users%lucas.zimmerman%Katalon Studio%Sanofi 1560%Sanofi 1560.prj/bin/lib/CustomKeywords.class’ not found.
Use your file explorer to make sure that this file exists at the mentioned location.